Inhibition of caspase-3-like activity reduces glutamate induced cell death in adult rat retina
Inhibition of caspase-3-like activity reduces glutamate induced cell death in adult rat retina
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DOI：
10.1016/s0006-8993(01)02485-4
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发表时间：
2001-06-15
期刊：
影响因子：
2.9
通讯作者：
Chan, SO
中科院分区：
文献类型：
--
作者：
Chen, TA;Yang, FS;Chan, SO
谷氨酸受体过度刺激引起的视网膜细胞死亡与程序性细胞死亡或凋亡有关。然而，对导致视网膜细胞死亡过程的细胞内事件知之甚少。在这项研究中，我们询问caspase-3家族半胱氨酸蛋白酶是否在暴露于过量谷氨酸后的成年大鼠视网膜外植体培养中调节细胞死亡。在短暂暴露于20 mM谷氨酸后3 h，在神经节细胞层中首次检测到DNA断裂的细胞，而在谷氨酸损伤后6 h，在内核层中首次观察到DNA断裂的细胞。通过识别caspase-3家族蛋白酶产生的肌动蛋白片段的fractin抗体免疫染色显示，在谷氨酸处理后40分钟可见caspase-3样活性。首先在神经节细胞层染色，然后在内核层染色，然后在这些层中出现DNA断裂的细胞。共定位研究显示，所有DNA断裂的细胞都呈fractin阳性，表明caspase-3家族活性参与了谷氨酸诱导的成年大鼠视网膜细胞死亡。此外，caspase-3家族成员的四肽抑制剂DEVD-CHO显著降低了分形蛋白染色，显著减轻了谷氨酸诱导的神经节细胞层和内核层细胞死亡和DNA断裂。caspase-1样活性抑制剂YVAD-CHO既没有降低分形蛋白染色，也没有显示出与视网膜相当的神经保护作用。我们得出结论，谷氨酸诱导的成年大鼠视网膜凋亡细胞死亡是由与caspase-3家族相关的半胱氨酸蛋白酶的特异性激活介导的，对caspase-3蛋白酶的干预可有效保护视网膜神经元免受谷氨酸兴奋毒性的影响。(C) 2001 Elsevier Science B.V.版权所有
Retinal cell death induced by over-stimulation of glutamate receptors is related to the programmed cell death or apoptosis. However, little is known about the intracellular events that lead to this cell death process in the retina. In this study, we asked if caspase-3 family cysteine proteases regulate cell death in an explant culture of adult rat retina after exposure to excessive glutamate. Cells with DNA fragmentation were first detected in the ganglion cell layer 3 h after a brief exposure to 20 mM glutamate, whilst those in the inner nuclear layer were first observed 6 h after the glutamate lesion. Caspase-3-like activity, as indicated by immunostaining of the fractin antibody that recognizes actin fragments generated by caspase-3 family proteases, was seen 40 min after glutamate treatment. Staining was first detected in the ganglion cell layer and then in the inner nuclear layer, preceding the appearance of cells with DNA fragmentation in these layers. Colocalization study showed that all cells with DNA breaks were fractin positive, indicating that caspase-3 family activity was involved in the glutamate-induced cell death in the adult rat retina. Furthermore, DEVD-CHO, a tetrapeptide inhibitor for caspase-3 family members, reduced dramatically the fractin staining and significantly alleviated glutamate-induced cell death and DNA fragmentation in the ganglion cell layer and inner nuclear layer. Inhibitor for caspase-1-like activity, YVAD-CHO, neither reduced the fractin staining nor showed comparable neuroprotective effects to the retina. We conclude that glutamate-induced apoptotic cell death in adult rat retina is mediated by a specific activation of cysteine proteases related to the caspase-3 family, and an intervention to the caspase-3 proteases provides effective protection to retinal neurons against glutamate excitotoxicity. (C) 2001 Elsevier Science B.V. All rights reserved.